1987-2009 Yamaha ATV YFM350X Warrior Raptor Service Manual, Page 390Get this manual
CHECKING AND CHARGING THE BATTERY Charging method using constant voltage charger
Measure the open-circuit voltage prior to charging
NOTE: Leave the battery unused for more than 30 minutes before measuring its open-circuit voltage
Connect charger and ammeter to the battery and start charging
Is the amperage higher than the standard charging amperage written on the battery?